The Anadolu Agency said the accident early Tuesday caused a large blast and a fireball that engulfed two passenger buses and other vehicles that were also traveling on the road near the town of Lice, some 150 kilometers (90 miles) north of the city of Diyarbakir.

At least 20 people were seriously injured and one of them later died in hospital.

The private Dogan news agency said firefighters took two hours to bring the fire under control.